The rapid advances in size and weight reduction of various electronic devices in recent years are leading to increased mounting densities for electronic parts, and the electronic parts and materials used therein are being required to exhibit a greater variety of properties. Printed circuit boards, in particular, being produced with smaller wiring areas and higher wiring densities, are being required to meet demands for multilayer wiring boards (build-up wiring boards), flexible circuit boards (FPC) and the like. Such printed circuit boards are produced using various adhesives or adhesive films. The resins used as adhesives are primarily epoxy resins and acrylic resins. However, all such resins have been inadequate from the viewpoint of properties such as heat resistance and electrical insulation.
Polyimide resins and polyamideimide resins are well-known as adhesive compositions that exhibit heat resistance and electrical insulating properties.    [Patent document 1] Japanese Unexamined Patent Publication No. HEI 11-217503